Electromagnetic sounding device



H. GERNSBACK. ELECTROMAGNETIC SOUNDING DEVICE.

APPLICATION FILED DEC. II, 1917.

PatentedSept. 28,1920.

I UNITED STATES PATENT OFFICE.

HUGO ennnssnox, or NEVJ YoRK, 1v,

ELECTROMAGNETIC SOUNDING DEVICE.

a l c tion filed December 11, 1917. Serial No. 206,636.

T 0 all whom it may concern:

8 Be it known that I, HUGO GERNsBAoK, a citizen of the United States, residing at New York, in the county of New Yorlqstate of New York, have inventedcertain new and useful Improvements in Electromagnetic Sounding Devices; and Ido hereby declare the following to be a full, clear, and exact description or" the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to mechanisms for practising telegraphy and more particularly for use in practising wireless telegraphy wherein the signals have a degree of continuity as distinguished from the sharp clicks from the ordinary telegraph soun'ders. In the present apparatus, each depression of the key results in the vibration of a diaphragm in synchrony with a succession of electrical impulses of a duration corresponding to the length of time the key is held depressed. The result is a sound similar in quality to that given out by the wireless telegraph receiver, but many times amplified. The result is accomplished by placing a diaphragm in the field of force of an electro- .aagnet, in the circuit of which and of a sending key, is a make-and-break mechanism entirely independent of the diaphragm but actuated by the same electro-magnet.

In the drawings Figure 1 is a .view partially in section and partially in side elevation showing the complete apparatus.

2 isa plan view with the diaphragm and casing cap removed.

Referring to the drawings, there is illustrated a base 5 of any suitable material at one end of which there rises an annular flange 6 that constitutes a cylindrical casing, the upper end of which is exteriorily threaded as shown at 7 to receive a cap 8 having a central opening in which is secured an amplifying horn 9. The extreme upper edge portion of the flange 6 is reduced in thickness as shown at 10 and from the lower face of the cap 8 there depends an annular flange 11 of the same diameter as the portion 10 and between which and the portion 10 is clamped a paramagnetic diaphragm 12 which is thus tree to vibrate.

A bridge piece 13 of insulating material is supported at one end upon a block 1a and is held in such position by means of a bolt 15 passed through the bridge plate, block, and

base 5, as illustrated. The other endof the b ridge plate, which extends diametrically of the cas ng formed by the flange 6, is sup ported upon a series of superimposed washers 16, 17 and 18, through which, the bridge diaphragm so as to effect its vibration with v out making physical contact.

-Beneath the bridge piece 13 is disposed a make-and-break mechanism including .a stationary metallic plate 22 one end of which is clamped between the fiber washers 17 and 18, the latter having a central hub that enters a corresponding opening in the plate 22 and abuts the washer 17 thus insulating the plate 22 from the bolt 19. Between the fiber washer 17 and the metal washer 16 is disposed a para-magnetic armature 23, the plate and arm having the usual platinum contact points as illustrated, and which lie normally in mutual contact. The parts are clamped in this correlation by means of the bolt 19.

The arm or vibrator 23 is within the field of the electro-magnet and it will be understood that when the magnet is energized, the vibrator will be attracted to separate the contact points.

Upon the base 5 exterior to the flange 6, there is disposed a post 24 that supports one end of a spring lever key 25 held thereon by means of a bolt 26 passed through the key, the post and the base, as illustrated. The key is provided with a platinum contact 26 which is normally out of engagement with a contact 27 in the form of a bolt that passes through the base 5.

Upon the base 5 are mounted binding posts 27' and 28 of which the post 27 is connected by a wire 29 with the bolt 26 through the medium of its nut as illustrated and thence with the key 25. The contact 27 is connected by wire 30 with one terminal 21' of the electro-magnet, the other terminal of which is connected by wire 31 with the arm 22. A wire 32 is clamped beneath the nut 19 of the bolt 19 and'leads to the binding post 28.

.Vith the construction above illustrated and described, it will be understood that the 7 posts 2 and 28' being in circuit with a source of electricity and the key 25 being depressed the electro-magnet will be instantly energized which will effect a synchronous movement of the diaphragm 12. At the same time, the vibrator 23 will be moved to disengage its contact from that of the arm 22, thus breaking the circuit. Thekey being still depressed the vibrator will instantly "return" to reenga-ge the'contacts at which timethe diaphragm will be released. Atfthe instant of reengagement of the contacts, the

electro-magnet will be reenergized and a second movement of the diaphragm and of raphy.

the Vibrator will result. This operation will Continue so long as the key is held depressed ceiver o eratin 'on five hundred c cles.

The advantage in the use of this instruent is that the sounds emanating from the horn, while being very much louder than from a; wireless receiver in use, are in tone v quality and physical character in all respects raphy.

similar to those received in wireless teleg- Inorder to reduce the field resistanceof the electro-magnet, a U-shaped paramagnetic plate 33 is sprung over the electromagnet and the bridge piece, one arm of the .U-shaped plate being secured against the lower end of the core of the electro-magnet through the medium of a paramagnetic screw 34: while the opposite arm terminates close to the upper end of the core. There is thus given a more intense field for actuation of the'diaphragm 12 while theintensity of the field atthe opposite end of'theelectromagnet is decreased so as to'insure rapid vibration of the spring plate 23 which is of ver light metal. l hat is claimed is: A device for producing sounds in imitation of wireless telegraphic signals, co'mprising an electro-magnet, a paramagnetic member 1n the field force between the poles of the electro-magnet and capable 01 absorbing a portion only or" the magnetic lines 7 of force of the field of the magnet and spaced at one end from a pole or" the magnet,

a diaphragm in the field or" the electro-magnet across the spacing between the last named pole and the paramagnetic member and a make and break mechanism in circuit with the electro-magnet and subject to lines of force exterior to the paramagnetic member. r,

' "In testimony whereof I afiix my signature in the'presence of two witnesses.

' Witnesses:

ERNA PIKE,

EDWIN Wool).

nueo ena sB oK 

